Just thought I would mention these two simple arguments. So simple that some people might just overlook them.
Since Mark has added serial command passing through the "serial=" parameter on the URL, you can use this to quit and launch the player software. This will probably require the developer software installation (which would allow you to drop to a BASH command prompt when not running the player software):
"http://empeg.ip.address/?serial=q" - will send a "q" quitting the player software. The empeg would be left sitting at a bash prompt (viewable from a serial connection).
"http://empeg.ip.address/?serial=player" - will send "player" and a carriage return (or linefeed - a RETURN nonetheless). This will relaunch the player software.
You can pretty much do whatever you would normally type on the command line over a serial connection, except you won't be able to see the output.
The above ability to quit the player softwre is suefull because it frees up a lot of CPU/disk I/O for HTTP streaming purposes. So you can make a small HTML file, toss it on the root of your player with a couple of links to do the quit and then a link to the "?playlists" directive.
Just don't tell other people about the "serial=" abilities if you don't trust them not to mount your partitions RW and then start deleting things - or running fsck, etc.
Bruno